How important is signal strength to the operation of a good responding carburetor?
A Signal strength was one of the key factors in developing the BLACK JACK carburetors. This was long before all the recent talk about signal strength and carburetor comparisons. Most tests are done at wide open throttle and without air filters. You need a big flow bench and high differential pressure, like 20 to 25 inches of water, to flow large masses of air down the carburetor. If you check signal strengths at wide open throttle you will see the numbers range from the 30’s to the 70’s at 25 inches of water pressure. Less at 20 inches of water and a lot less at 5 or 6 inches of water, this being measured at the main circuit and using inches of water as a unit of measure. The low speed signals will range the mid 20’s to the mid 30’s at the same 25 inches of water. most of the variation of the pilot circuit is due to the different types of high speed fuel discharge methods being used and how the air flowing around them acts upon the low speed passages. One must remember that there is a
